How To Build An Acoustic Guitar. Episode 11 (The Kerfing)

[@andrewmundenandcadfellmast4624]

Okay, I'll be "that guy" lol. What you did is add traditional lining. What you call kerfing is actually kerfed lining. Kerfing is the process of cutting kerfs (saw blade width slots) into lining timber. Bending the timber linings is how guitars were originally made. Right, got that off the chest lol. Having said that, Im really enjoying this build, it looks great. Cheers

[@stephen3073]

Right! A "kerf" is the slit left by a saw blade cut. Solid linings do not have kerfs, hence "solid kerfing" is non sequitur. Not to be picking nits here, but the proper terms are "kerfed linings" or "solid linings".

[@Andy_Classic]

He mentions this at about 11:45

[@andrewmundenandcadfellmast4624]

@Nathan Something ha ha, some do, but most just call it lining lol

[@alecr666x]

You just saved me from being "that guy". Was going mad every time he said "solid kerfing" 😂. It's the same when people say they're drinking out of a plastic glass. Loving this series of videos though.

[@myeyesarewaiting]

you know, one of the best things about these videos is seeing people at work, happy, and loving what they do.

[@stephen3073]

One thing I'd like to point out is that the width of the gluing surface of the rims (the sides + the lining strips glued in place) should be kept to somewhere between 1/4" and 5/16", depending on the size of the sound box. If the gluing surfaces for the top and back are too wide, that will tend to impede the sound-producing movement of the back and the top. You need to keep this glue join secure, but not over-built! That's important, because when you buy pre-made linings from StewMac or LMI, they are sized for guitars made with SINGLE-THICKNESS SIDES, not for the thicker laminated sides. If I'm not mistaken, LMI and StewMac make their kerfed linings about 6mm (.24 inch) thick; add that to 3.5mm double sides, and that gluing surface will be 9.5mm (.37 inches) thick. That will really start to have a "tightening" effect on the top and back plates. If you build with double sides, like Driftwood, those store-bought linings could turn out to be quite a bit wider than they need to be, causing some diminution in the air-pump action of the top and back plates. This is why I always make my own linings, so the total built width of the gluing surface of the rims will be between 1/4" (for smaller guitars) and 5/16" (for larger sound boxes). You can see in this video that Chris's linings are quite thin, so that the stacked double sides + the lining strips will not be too wide. So, do as Chris and Matt do, and make your own linings! Chris just showed you how easy it is, using the side bender. Store-bought may be quicker and easier, but shop-built is better!

[@DriftwoodGuitars]

100%. I was trying to make that point, but you said it way better haha

[@danawheeler6517]

In the beginning classical guitar linings were created using individual little blocks called tentellones. These were painstakingly glued in one at a time. So kerfed linings today are a short cut tying the blocks together for easier gluing.

[@scottkidwellmusic9175]

"Clamp on! Clamp off!" Pretty cool! Thank you 🙏🙏🙏

[@dankygnome5083]

Love you bro! I’m at this stage in my first ever build. 🙏🏻 watching your videos helps so much…

[@arcarioandsons]

I love your channel. You put out great information for sure but just the feeling of hanging out with you guys for 30 minutes or so, it's so relaxing. You guys are both so charming and seem to have a lot of fun, so by the end of your videos I've always got a big smile on my face. You guys make me feel good, and I can't tell you how much I appreciate it! I Love you guys!

[@DriftwoodGuitars]

Aw man, thank you so much! Happy to have you hanging with us.

[@arcarioandsons]

@@DriftwoodGuitars I'm in the process of finishing outfitting my new shop and cutting up lumber behind my shop in northeast PA. I'm cutting up 200+ year old white oak, all kinds of cherry, hickory, walnut, and I'm hoping to master identification of decaying tulip poplar for crazy colors and figure. I'll need other builders to help me figure out what the true potential of those woods is gonna be, oak worked for Brian May right? Plus you've never seen oak with this figuring... Hickory is the same hardness as most good fret woods... I would gladly send you some wood just on the chance of you mentioning it on your channel if you're interested.

[@bldallas]

As this guitar continues to cone together, I’m more and more amazed at your thought processes and craftsmanship. Really great stuff, Chris! Very cool.

[@DriftwoodGuitars]

Glad you enjoy it!

[@newpatch36]

@driftwoodguitars, you're right that kerfing is a woodworking operation - cutting halfway through the piece to allow for bending. This technique is often used for curved risers on spiral staircases.

[@dalgguitars]

Re-watching the video. How many of those little clothespin style clamps (for the kerfing/linings) should I get?

[@jimmydevine4862]

Hey guys. Newcomer just catching up here. Great channel. I would give up a toe to have your talent! Just curious, is there a tonal change between slotted to in-slotted merging?

[@sfcmp7005]

Your comment about what your mom said when she seen you do that spitune thing with the glue brought back a nice memory for me. My name is Chris as well, and my mother always used to say "Christopher", if I did something she didn't approve of. I believe I'm probably a generation older than Chris, but it just goes to show that mothers of all generations sometimes thought the same. Thanks for the nice memory!! 😎

[@HarryNicNicholas]

i have an epiphone AJ220 and the kerfing is back to front on it, that is the kerf is against the side and the "back" faces you. i have a 69 epi texan too, so next time it comes out of the case (i have 11 guitars atm) i'll have to check.

[@scaira60]

Chris I just want too Thank You for turning me onto those mini clamps from Amazon, I had previously bought them from stew Mac for around $15 for 10-clamps. God Bless brother🙏🙏🇺🇸🇺🇸🇺🇸🎸🎹🎼👨🏻‍🦯

[@bradmortensen365]

In episode 4 you mentioned a 35 foot radius for the top and in this episode you say a 30 foot radius. Which is it? Why the 35 or 30 foot radius typically I have heard of a 25 foot radius? Also do you know why different radiuses are used for the top and back? Really enjoy these videos, Thanks!

[@santiagocercavins]

What if you put 2 kerfings like “laminating” so that you have more meat to glue the top? … is that overkill? … I’m just curious and a total fan of yours !

[@Super_Nope_13]

I laminate linings for my guitars. you basically just laminate another side and then rip it into lining strips afterword on the bandsaw. combined with laminated sides and tucking linings into your head and tail blocks, makes for a very stiff rim set.

[@DriftwoodGuitars]

Correct! Lots of people do that.

[@hymnplayer]

I really enjoying watching your videos. As a hobbyists builder I like using reverse kerf linings for adding stiffness to the sides.

[@MobRules2112]

Have you tried to glue the "kerfing" at the same time you laminate the sides?

[@alandust2188]

The old saying is, "To teach, is to learn". On your side bender, did you use an lmi made insert or did you make your own? Thanks!

[@DriftwoodGuitars]

I made my own.

[@artcarney4171]

Building a ukulele , would you do laminate sides ? Great channel guys 🤙

[@RickDeevey]

So doesn't traditional kerfed lining have a bit more gluing surface on the top side, which might be more beneficial to attach the top, especially when you rout away channels for binding and/or purfling? Sometimes they rout right back to the lining itself for the binding channel, so there's no side wood left where the top and back attach. I know it never seems to be an issue (and it certainly won't be with your thicker laminated sides), but I still wonder about its structural strength at that point. Also, as a side question, do you think purfling on the top serves any other purpose than decorative? Could the thinning of the top at the edge under the purfling perhaps make the top more flexible around the edge? I'm considering the top to be like a speaker cone in this respect, or is that an inaccurate way of thinking about it?

[@stephen3073]

That's a very interesting question! I bet Chris agrees- On your next build, after you close the box, but before you do the binding work, tap on the top and back a lot, to get a feel for how responsive that percussive note sounds. Kinda dull and unfocused, right? Then, after your binding work is all done and flat-sanded, do the tap thing again. I'll bet you a week's pay that the tap tone will be MUCH MORE lively! You don't really get a true feel for how responsive the box is until AFTER you do the binding work! I think the bindings and purflings actually have the structural effect of freeing up the movement of the top and back.

[@WoodshedCustoms]

Really enjoying these. Makes me want to start my SM OM kit I have sitting in my garage for too long. You are definitely filling my head with great ideas, but still think I need to stick to the plans. Anyway, thank you guys.

[@DriftwoodGuitars]

Glad you’re enjoying it! Go out there and get started! You won’t regret it.

[@christopher-miles]

...i hate when ma said, that; "CHRISTOPHER! WHAT HAVE YOU DONE THIS TIME?." LOL

[@DriftwoodGuitars]

We now sell hand selected and resawn Tonewoods on our website! Each piece was found by Chris Alvarado, and almost always has a story to go along with it. Go check out the selection at www.driftwoodguitars.com/tonewood

[@activese]

Questions: The commonly used kerfing or kerfed lining, I believe that is wider at the top than the solid linings, you used here?, because then the solid linings provide less surface for the top to be glued, or maybe make them, with some sort of an wider side or angle, at the contact point, more than the 2.5mm to equal common kerfed lining? But I really like that your solid linings save, in all your explained differences, from common kerfed linings, and you can afford and provide better wood quality for it.

[@nolimitsldr]

Nice! I’ve seen all your videos, love it. I just don’t know how you manage to get these guitars done when you’re always off to the races. 😂

[@dalgguitars]

Thank you so much for your videos!

[@dymbag1]

Just wondering what buffing wheels you use?

[@Andy_Classic]

So what's the difference between Solid Kerfing, regular kerfing and reverse kerfing tone wise?

[@chriskettlewell801]

Curious. You talk about how solid kerfing adds to the strength in a way traditional kerfing doesn’t. But what about reverse kerfing where the slots are against the guitar sides and the join is on the opposite side of the kerfing from the side itself. Wouldn’t that give the same strength benefits while giving a bit more thickness for glueing top to sides and one less thing to have to bend?

[@andresbide]

Hey Cris. What do you think on making a groove in the back and neck blocks to insert the kerfing a little bit? Could add some stiffness? Cheers from Uruguay

[@DriftwoodGuitars]

Solid idea!

[@mikegray-ehnert3238]

Hasselbeck is indeed a good way to roast a bird, plus you get the raw back to freeze and keep for making a rich stock. For chicken, using kitchen shears, cut the backbone out along both sides, flip the bird over and flatten by cracking the breastbone by pressing on the "sternum," breaking the breastbone. Tuck the wing tips under and rotate the legs in so the legs are flat. Season as you like, roast for about 1:15, oiling the skin a bit to crisp. This allows the breaststroke to cook at the same rate as the thighs/legs.

[@SkyscraperGuitars]

Great insight! Sometimes we actually learn more by teaching than we do as the student. :D.

[@nipunlokuwithanage3433]

2:45 The puppyyyyyyyyy 🥺

[@DriftwoodGuitars]

Yeah! That’s Charlie, our new shop dog!

[@tyhubb]

I believe the "kerf" is the amount of material "eaten" by your blade. Typical kerf is about 1/8" on most saw blades. So all those lines that are cut out are the kerf cuts....hence kerfing I believe?

[@wesmrtz16]

When you run a saw of any kind through a piece of wood, the gap the saw made is called the Kerf.

[@eriziasbasses]

You are correct by using the word kerf. Usually, lining that is sliced is called kerfed lining. ;)

[@judsonriviere490]

I’ve only heard people refer to that as a solid lining. I’ve even seen some people not like the term kerfing altogether, and calling ‘traditional kerfing’ kerfed linings..Just semantics

[@olfl4160]

Awesome video as always, when I retire this is what I will do. Do you think that the laminated sides you are using are eliminating the tonal differences between different woods on the sides? I mean, the difference in tone probably comes down to resonance and vibration characteristics of the wood. And the laminating effectively removes those parameters as all side woods would then become equally super stiff?

[@TheVectorious]

I think the sound comes from the top and the back. Having the laminate sides allows the energy to pass through them and not get lost and be utilized by the top and back.

[@dougstrong5386]

To be fair, solid kerfing is cheaper if your labour isn't included. Seems relevant for those who might ask for it just to see it could add cost.

[@sigfreed11]

How does the traditional lining increase side strength when kerfing doesn’t? Kerfing where it has been “kerfed” is about as thick and contiguous as traditional is, yeah?

[@newpatch36]

When lining is solid as shown in the video then all the wood fibers are continuous and inherently stronger. When lining is kerfed it has a bunch of cuts halfway through the lining, so the grain is no longer continuous and strength is lost.

[@josephdhemphill87]

I was actually surprised that you were only at 2.5mm for your linings. Is that because of your current double side thickness is much thicker then a non laminate side guitar, or do you think 2.5mm is enough gluing real estate for a more traditional non laminate side setup? When you were doing non laminates, were you doing solid linings?

[@josephdhemphill87]

Or would you just suggest doubling up the lining?

[@VAXHeadroom]

Hey Chris: Why not just put the 'kerfing' in the vacuum bag with the sides and bend and glue it all up at once? Save you the separate bending, gluing and clamping steps...

[@DriftwoodGuitars]

This is the second suggestion for this and it’s a solid idea. I’d need to prototype the method, but there’s something there to that.

[@jonahguitarguy]

It's lining, the stuff with cuts in it is called kerfed lining. I'm not sure why you didn't make your own kerfed lining it's not difficult or that time consuming. Also wondering why the lining was placed proud of the sides when they have to be sanded down at least to the side material. Obviously they should not be low but 2mm seems like a lot of extra work in sanding or planing. But hey, what do I know you're the guy that gets 10K for one of these babies.

[@jonahguitarguy]

@@nopinionocomnt, sure, if that’s what you want to do.

[@embwee]

I'd be nervous that solid lining gives less surface on which the top is glued, especially without laminated sides.

[@DriftwoodGuitars]

With the laminated sides, its the same total glue area as non laminate sides a traditional kerfing. If you wanted solid kerfing and no laminate sides, you'd need to double the solid kerfing thickness.

[@markmccawley2526]

Thumbs up for Mom!

[@48gibby1]

A matter of terminology: a kerf is a sawcut, Therefore, solid kerfing is a contradiction in terms. The lining is either solid or kerfed.

[@rhettbh]

Monster or ghost in background at 2:47

[@stephengent9974]

Traditional kerning must stiffen the sides also. Solid kerning would be stiffer. Traditional kerning takes a lot of processing, which is why pre=made is expensive. I would like to see a guitar made using paper to stiffen the walls. Should work well and be lighter too

[@harperswood3509]

Re: Kerfing. I always heard it called "lining"

[@nolimitsldr]

Ok I have a serious question…I’ve noticed you don’t spread the glue to cover the whole surface. Have I just been wasting time?

[@bryanwang9095]

Am wondering about this too

[@DriftwoodGuitars]

The way I see it, in a situation like this, the act of clamping the kerfing spreads the glue and it’s not a structural load component of the guitar, so perfect glue spreading isn’t an issue.

[@nolimitsldr]

@@DriftwoodGuitars But exposed joints like the head stock cover plate or binding you would do a total spread?

[@russellharris5072]

I can't visualise how the old builders would do that with hide glue,maybe they used fish glue which has a longer set up time......................................

[@josephnorton1996]

...guitar stuff is awesome. But seriously, what kind of taco place is closed on tuesday. That's just wrong.

[@DriftwoodGuitars]

Right!?

[@zaredshawver9496]

I was getting mad stressed when you kept pausing to talk during the glue up. Got real concerned about open time. Not quite into the yelling at the TV phase, but definitely in the head shaking in confusion phase.

[@DriftwoodGuitars]

A few minutes of open air time for a non structurally loaded part isn’t a big deal haha. I get it though.